When a wiring design of a semiconductor package is observed, ground patterns disposed in order to dissipate heat or return signals may be confirmed, in addition to signal patterns, which are fine circuit, disposed in order to transfer the signals. Since a remaining rate of a copper foil is very high in a ground region, a risk of interlayer delamination is high. In order to solve such a problem, a degas design having a circular or linear shape is reflected in a design to improve close adhesion between an insulating layer and the copper foil and allow a degas component discharged from a lower insulating layer to be easily discharged.
However, such a degassing hole is filled with an insulating material, such that an insulating layer dent phenomenon may occur in a surface of an insulating layer. In this case, patterns disposed on the insulating layer are broken or close adhesion between the insulating layer and a dry film resist is reduced due to a step of the surface of the insulating layer. Resultantly, a plating solution permeates into the insulating layer and the dry film resist, such that a defect such as a short-circuit may occur.